Christine Jones
Dr. Christine Jones
Senior Astrophysicist
Smithsonian Astrophysical Observatory
60 Garden Street, B-401 | Cambridge, MA 02138 MS-02
RESEARCH TOPICS
Binary system with matter from the companion star falling toward and accreting onto the orbiting compact object, producing X-ray emission
Uhuru, Ariel V and optical ground-based observations led to the determination of a 3.4-day binary period for the X-ray binary system 4U1700-17 and to the identification of its optical counterpart. Other discoveries were extended periods of low optical luminosity for Hercules X-1, lasting as long as 5.5 years, and a 600 day recurrence period for the X-ray transient 4U1630-47.
Contours of the X-ray emission from the hot gas around two early type galaxies
Einstein imaging observations led to 1) the discovery of hot gas halos in early type galaxies and groups that are gravitationally bound by dark matter halos, 2) the identification of multiple mass components in clusters of galaxies ("double" clusters), and 3) showed that 40% of clusters at the present epoch have significant substructures from ongoing mergers and are not relaxed systems. ROSAT observations were used to make the first detection of cavities in the hot gas around NGC1275.
Dark energy constraints in a flat Universe
The analysis of Chandra and XMM-Newton observations showed: 1) there is a significantly larger number of massive clusters in the present epoch (z<0.25) than at earlier times (z=0.35-0.90), and 2) from the sensitivity of the cluster mass function to cosmological models, the existence of dark energy is required.
Cavities in the hot gas around NGC4636 produced by outbursts from the central SMBH
Chandra observations showed that the amount of cool gas in the cores of clusters expected from "cooling flows" was significantly less than expected. The primary way to heat the cooling gas was found from Chandra observations to be outbursts from supermassive black holes. Evidence of the AGN outbursts were found primarily in the form of cavities, not only in clusters (e.g. Hydra A), Perseus, (Fabian et al., 2000 MNRAS Letters, 316, 85), but also in early type galaxies (M84, NGC4636, Centaurus A) and galaxy groups (Fornax, NGC507, NGC5846).
Structures in the hot gas of the elliptical galaxy M60, due to its infall toward M87.
Chandra observations of the elliptical/S0 galaxies M86, M60 and NGC4472 in Virgo, NGC1404 in the Fornax cluster and the spiral galaxy ESO137-001 in the cluster A3627 show spectacular "tails" of hot gas ram-pressured stripped from the galaxies as they move through the cluster ICM.
Bullet Cluster
Red - hot gas. Blue - dark matter.
The Bullet Cluster (1E-657-56) is undergoing a major merger of two massive subclusters. HST images (PI Jones) were used to map the distribution of dark matter in the cluster, which showed that dark matter has a different distribution from the hot gas, which comprises the bulk of the visible mass.
Foreground galaxy clusters magnify high redshift background objects. Circles mark redshift 6 (cyan), 7 (magenta) and 8 (yellow) gravitationally lensed objects
Jones and her colleagues studied the "double quasar" Q0957+561 with the Einstein HRI, the ROSAT HRI and with Chandra ACIS-I. In addition to detecting each of the quasar images, X-ray and radio emission is detected from the quasar jet.
Currently, Jones is part of the RELICS project which observed 41 massive clusters with HST and Spitzer IRAC and has so far identified more than 100 lensed galaxies at redshifts greater than 8, which are luminous enough for detailed study with JWST.